A household and/or professional laundry machine—such as a laundry washing machine and a laundry washing/drying machine—typically comprises a washing tub, enclosed in a casing, that houses a rotatable drum in which the laundry can be loaded/unloaded, and accessible by a user for loading/unloading the laundry through a loading/unloading aperture selectively closable by a door.
During operation, washing liquid (e.g., water or water mixed with washing/rinsing products) is introduced in the tub of the laundry machine by means of an inlet hydraulic system fluidly connected to the tub. Subsequently, a washing phase starts in which the laundry previously loaded into the rotatable drum is washed thanks to the chemical reactions exerted by the washing liquid, supported by the tumbling action caused by the rotation of the drum.
At the end of the washing phase, waste liquid (i.e., the washing liquid mixed with dirt particles removed from the laundry and possibly fluff lost therefrom) is drained from the washing tub before starting a rinsing phase of the washed laundry typically followed by a spin-drying phase. Furthermore, also additional waste liquid expelled from the washed laundry during the spin-drying or rinsing phase is discharged at the end of the laundry machine operation in order to avoid waste liquid stagnation, correlated unpleasant smells and dirt deposits within the drum and/or the tub.
Therefore, the laundry machine is provided with a draining system adapted to drain waste liquid during the operation of the laundry machine. Particularly, such draining system is selectively fluidly connected to the tub of the laundry machine in order to receive the waste liquid.
The draining system usually comprises a discharge duct (such as a flexible hose), which, at one of its ends, is connected to a discharge hole at the bottom of the washing tub for discharging the waste liquid. At the other end, the discharge duct is connected to a pump assembly adapted to drain the waste liquid from the washing tub. Such a pump assembly usually comprises a filter (for blocking small objects and/or fluff) and a drain pump (that pumps liquid out of the washing tub). A valve member is usually provided in the discharge duct in order to fluidly separate during a washing procedure the draining system from the tub. Finally, a discharge hose connects a pump assembly outlet to a house draining pipe system for disposing the waste liquid.
Typically, the discharge hole is surrounded by a drain collar, which surrounds the discharge hole and is advantageously connected to the discharge duct of the draining system.
As known, the discharge duct has to be properly connected to the tub in order to avoid waste liquid leakages, which may lead to laundry machine malfunctions (e.g., due to waste liquid leakages on electrics or electronics component parts), annoying drawbacks (e.g., waste liquid dispersed on the floor). Many types of discharge ducts are known, each featuring peculiar shapes and constitutive materials. Therefore, it is necessary to use a specific tub adapted to the particular discharge duct type to be mounted thereto.
For example, a flexible hose may be fastened to the drain collar of the tub by means of a hose clamp. Conversely, in the case of a manifold made of hard material, such as a plastic polymer, a hose clamp does not provide a suitable fastening (since the plastic polymer does not deform as the elastomeric material does upon the fastening of the hose clamp) and other expedients have to be applied, such as screwing the manifold to the tub at the drain collar.
Consequently, the discharge hole and the portion of the tub in which the same is provided has to be specifically manufactured according to the discharge duct type (i.e., made of elastomeric or hard material) to be connected to the same, which requires different manufacturing lines or different manufacturing periods on a same manufacturing line. This requires an accurate laundry machines manufacturing planning, which may cause manufacturing costs to increase.